1. Field of the Invention
The present invention generally relates to computer-aided design (CAD) applications. More specifically, the present invention relates to a method for synchronizing object style definitions used by multiple, discrete drawing files that are part of a design project.
2. Description of the Related Art
The term computer-aided design (CAD) generally refers to a broad variety of computer-based tools used by engineers, architects, and other design professionals. CAD applications may be used to construct computer models representing virtually any real-world construct. Commonly, CAD applications are used to create computer models of construction projects, e.g., residential homes, office buildings, roadways, bridges, etc. A model of such a project may be used to generate engineering and construction documents and to provide users with a visual display of the project such as a rendering of the interior design choices for a floor of a building.
Typically, a design project may include hundreds, if not thousands, of CAD drawing files, which may each provide a drawing or model of some aspect of the project. For example, a design project modeling an office building may include a drawing file for each floor of the building, for each building sub-system, and for the exterior design features. Further, each floor of the building may itself be represented by multiple drawing files, e.g., drawing files for individual offices, common areas, etc. Collectively, the CAD drawings provide a model of the different aspects of a design project from many different perspectives.
Using multiple, independent CAD drawings for a design project has several advantages. First, using many smaller files typically increases the performance of a CAD application, as the application does not have to parse a single monolithic project file to access some aspect of a drawing. Second, multiple users may edit different drawing files simultaneously.
To compose a CAD drawing, some CAD applications provide users with a catalog of drawing objects related to the architectural, engineering, and construction elements used in a particular project. Drawing objects are used to represent the geometry, shape, and location of an object within the CAD drawing. Drawing objects may also represent non graphical data such as data related to the manufacturer, fire resistance rating, schedule identification, etc of a component represented by a drawing object. The drawing objects allow a designer to compose a CAD drawing from objects that correspond to the components used to build the real-world structure, rather than from individual lines or geometric shapes. For example, a CAD drawing of a floor of an office building may include “wall” objects representing the exterior and interior walls and “door” objects to represent doors.
Further, some CAD applications allow users to define an object style that should be used for instances of a drawing object included in a CAD drawing. Generally, an object style refers to a set of parameters that define the appearance, function, or properties of a drawing object when it is used a CAD drawing. For example, a CAD application may provide a variety of door objects to represent different types of door constructions such as single-doors, double-doors, bi-fold doors, etc. Users may define an object style for aspects of these door objects such as the default frame dimensions, the hardware groups, the construction materials, or the display properties of the object such as a color or hatch pattern to use in screen displays or construction documents. Using object styles relieves the designer from having to repeatedly specify the same characteristics when including an instance of the drawing object in a CAD drawing. Once an object style is defined, it becomes part of the data associated with a CAD drawing. Thus, when the CAD drawing is shared with other users, the definition of an object style is always available. Also, changes to the object style defined for a given drawing object affect each instance of the drawing object included in a given CAD drawing.
As stated, using multiple drawing files has clear advantages. At the same time, when multiple CAD drawings are related to the same design project, the object styles within each CAD drawing may need to be synchronized with one another. For example, a given enterprise may desire to use the same object styles in all CAD drawings related to a particular design project. Coordinating different versions of an object style defined in multiple CAD drawings can be both difficult and time consuming, as the object style may have to be updated in each CAD drawing individually. Further, during the course of a design project, the project standards may change. Thus, a great deal of time and effort may be directed to coordinating object styles or to propagating changes made to the definition of an object style across a set of CAD drawings.
One approach to managing object styles is to have each CAD drawing reference an external definition for an object style. However, this approach creates a critical dependency on the externally defined object style and requires the definition to be available when any CAD drawing that references the externally defined object style is archived, transmitted, or opened by any user. Another approach is to provide a fixed collection of object styles to use in a design project. This approach, however, fails to allow users to create custom object styles for different design projects.
Accordingly, there remains a need for a way to establish, maintain and synchronize the definitions used for object styles and display settings across multiple CAD drawings associated with a design project.